Power Steering Box Interchange???

I was wondering if a power steering box from a 1976 Aspen with an 833 4 speed would interchange into a 1973 Duster with factory? V8 power steering? The box on my Duster is leaking at the return line and even though I have tried replacing the two 'O" ring seals, I cannot get the damn thing to stop leaking. At this point, I just want to change out the box and was wondering if this style box would fit? Please help if anyone out here knows, or if anyone out here has a power steering box from a 73-74 Duster with a V8 then I would be interested in purchasing it. Or where I can order these O ring replacement seals? Thanks in advance.